Communication system



STAT/0N B Oct 6, 1942 H. J. NlcHoLs ETAL 2,297,795

COMMUNICATION SYSTEM Original Fi'led Aug. 17, 1940 ll'Shee'cs-SheeiI l l molens Oct. 6, 1942. H. J. NICHOLS ETAL COMMUNI CATION SYS TEM Original Filed Aug. 1'7, 1940 11 Sheets-Sheet 2 Oct. 6, 1942. H. J. NICHOLS ET AL COMMUNICATION SYSTEM Original Filed Aug. 17, 1940 l1 Sheets-Sheet 3 llllllllll i INV EN TOR ,1M/PA 0ct. 6, 1942. H. J. NlcHoLs ETAL 2,297,795

COMMUNICATION SYSTEM Original Filed Aug. 17, 1940 ll Sheets-Sheet 4 FIGA:

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Oct 6, 1942 H. J. NlcHoLs Erm. 2,297,795

COMMUNICATION SYSTEM Original Filed Aug. 17, 1940 ll'Sheets-Sheet 5 Oct. 6, 1942. H. J. NICHOLS ETAL 2,297,795

COMMUNICATION SYSTEM Original Filned Aug. 17, 1940 ll Sheets-Sheet 6 0ct.6,1942; H. J. .HOLS mL 2,297,795

COMMUNICATION SYSTEM Original Filed Aug. 17, 1940 11 Sheets-Sheet '7 ,56 F'IGM.'

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Oct. 6, 1942. H. .1. NlcHoLs ETAL 2,297,795

COMMUNICATION SYSTEM Original Filed Aug. 17, 1940 1l Sheets-Sheet 8 FIG. I0.

INVENTORJ H/MY J NICHOLS BY- m ATTORNEY- Oct. 6, 1942. l H. J. NICHOLS ET AL COMMUNICATIGNSYSTEM Original Filed Aug. 17, 1940 ll'Sheets-Sheets ATTORNEY.

0d 6, 1942- H. J. NICHOLS ETAL 2,297,795

COMMUNICATION SYSTEM Original Filed Aug. 17, 1940 `l1 Sheets-Sheet lO INVEN TOR5 ATTORNEY.

Oct. 6`, 1942.

H. J. NICHOLS ETAL COMMUNICATION SYSTEM Original Filed Aug. 17, 1940 1l Sheets-Sheet l1 m k m TORS N/CHOLS ATTORNIY.

Patented Oct. 6, 1942 UNETED STATES ri-,TENT OFFICE COMMUNICATION SYSTEM Original application August 17, 1940, Serial No. 353,113. Divided and this application June 14, 1941, Serial No. 398,069

3 Claims.

The present invention is a division of the copending application of Harry J. Nichols and Henry L. Tholstrup, Serial No. 353,113, filed AU.- gust 17, 1940, which relates to interoiiice or interstation communication systems and more particularly to communication systems for interconnecting separate typewriters, of a certain standard construction, modified vto conform to a telegraphic keyboard wherein the operation of any one typewriter in a normal manner, can be isolated, at will, from the operation of the system to permit ordinary individual operationA of the respective typewriters or, on the other hand, 0peration of one typewriter in the normal manner can be utilized to locally produce a copy at a sending station, of the intelligence to be transmitted, and to simultaneously operate a second or receiving similar typewriter or a plurality oi such receiving typewriters at remote points. In like manner, each of the plurality of receiving typewriters can be utilized, when desired, as sending typewriters, and means are provided for break-in by a receive station, so that the direction of transmission can be reversed when necessary or desired.

In devices of the prior art wherein interoiiice messages have been transmitted, special machines which are not the usual standard equipment of business oiiices have been employed. There have also been previously provided electrical interconnecting systems for standard typewriters, but such systems have generally required an extensive rebuilding of the mechanical structure of the typewriter itself, to adapt it to such a system.

Accordingly, one of the objects of the present invention is to provide novel means used for interconnecting and operating two or more standard office equipment typewriters, such as the well known Electromatic typewriter, modified to conform to a telegraphic keyboard so that such an instrument is utilized, merely with parts of the original machine omitted and with very little additional equipment, in an interoiiice communication system, to produce speedy and accurate transmission and reception of messages and the device is so constructed that a great part of the additional equipment is incorporated within the ambit of the typewriter frame.

Still another object is to provide a system oi interoice or interstation communication including at least a pair of typewriters at different stations, each having a modified keyboard, means controlled by a selected character key for proillustrated in the accompanying drawings, which` ducing a characteristic combination of signal 5.3

code elements, an electrical connection between the respective typewriters comprising one signal channel over which the code signal elements of said character are sequentially transmitted, novel start-stop, send-receive distributor means for sending or receiving, respectively, at each station, and in synchronism, the code elements comprising a characteristic signal, and mechanical translator means controlled by received code elements for translating the same and selectively releasing a seeker lever to operate that key bar only, which corresponds to the key depressed at the sending station.

A further object is to provide a novel distributor for sequentially transmitting signal elements in accordance with the permutations set up by a selected character key.

Still another object is to provide novel distributing means including a novel ranging mechanism.

Other objects of the invention will be pointed out in the following description and claims and disclose by way of example, the principle of the invention and the best mode which has been contemplated of applying that principle.

In the drawings:

Fig. 1 is a diagrammatic view illustrating teleprinting devices such as typewriters suitable for ordinary ofiice work and also utilized in the production of code signal permutations representative of a character and also controllable by remotely originating signals to type a character, and means for electrically interconnecting a pair of such devices by a minimum number of signal channels for signal transmission therebetween, the translator and permutation units being contained within the framework of the typewriter.

Fig. 2 is a diagrammatic view, in skeleton outline only, illustrating fundamentally how the operations, at the send station, of a character key produces a code permutation of signal components representative of the particular character, which components, by means not shown in Fig. 2,

' in turn are relayed, in seriatim, to the signal channel, by a send-receive distributor assembly, and also illustrating fundamentally how a corresponding key bar is operated by a seeker lever corresponding to a characteristic signal received from a remote station, after said signal has been translated, to thereby select the corresponding seeker lever.

Fig. 3 is a schematic diagram, illustrating in skeleton outline the essential elements of a complete communication system including separate transmitting and receiving stations, respectively, with the start-stop clutches in the preliminary stop position and illustrating the signal channel between the stations.

Fig. 4 is a schematic diagram, generally like Fig. 3, but illustrating in greater detail circuits and elements of the transmitting and receiving mechanisms and including the circuits for break-in and keyboard lock-out or latching.

Fig. 5 is a fragmentary perspective View illustrating diagrammatically the mechanism forproducing keyboard lock-out or latching,

Fig. 6 is a diagrammatic view-illustrating. the

means for and manner of operation ofthe' contacts comprising a transmitting or a receiving distributor, and the ranging mechanism for adjusting the timing of the distributor.

Fig. 6a is an end View of the device or Fig. 6.

Fig. 7 is a perspective view illustrating the translator unit, the seeker levers and the mechanism for operating the print or. drop bar.

Fig. 8 is a side.elevation,. illustrating in more detail, th-e mechanism for operating the print or drop bar.

Fig. 9 is a fragmentary side View, partly in section, of the device of Fig. 8.

Fig. 9ak is a detailed view oi the piston element of Figs. 8 and 9.

Fig. 9b is a detailed view of the combined pin andpivot element of Figs. 8 and 9;

Fig. 1i) is a schematic View illustrating fundamentally the manner of operation of the actuating mechanism for the print ordrop bar under the control of a timed local impulse.

Fig. 11 is a plan View of they translator unit, A

in part, illustrating.schematically'the latching of a permutation slide bar by a translator magnet latch.

Fig. l2 is a front view of the device of Fig. 11 and illustrating further details of the translator unit.

Fig. 13 is'a fragmentary sectional View illustrating Vthe rollers locatedbetween the. permutation bars.

Fig'. 14 is a plan view of the translator unit, in part, illustrating schematicallyV the release of a permutation slide bar by a translator magnet.

Fig. 15 is a front viewof the-device of Fig. 14, and also illustrating schematically the restore magnet and its armature for resetting the permutation slide bars.

Fig. 16 is a diagrammatic View, illustrating a part of a circuit associated with a translator magnet.

Fig. 17 is a side'elevation, in section, oi one form of novel start-stop, single revolution clutch mechanism and including the transmitting and receiving cams, the latch contact operating cam, and the circuit breaker cam.

Fig. 18- is a perspective view illustratingthe construction oi the spider of the clutch mechanism.

Fig. 19 is a partial'sectionalview, illustrating the position of the clutch drivingpins, with relation to the spider and a driving'cup, when the clutch is disengaged.

Fig. 20 is a-` partial'sectional view illustrating theclutcli controlling disk'mounted on the spider, andthe manner'inv which the controlling diskactuates the clutch drivingpins to: the disengaged position of Fig. 19.

Fig. 2l is a view similar to Fig. 20 but with the controlling disk advancing the driving. pins to their engaged position.

Fig. 22 is-a view similarto Fig. 19 but with the 75 driving pins in the engaged or locked position of Fig. 21.

Fig. 23 is a sectional view illustrating the latch contact operating cam, the controlling disk and the accelerating spring in position.

Fig; 24 is a sectional view of the latch contact operating cam hub and the clutch spider, and the detent pawl for holding the parts in stopped position.

Fig. 25,V is a diagrammatic View illustrating the coaction of the start-stop magnet, start-stop magnet armature andthe stop pin of the clutch controlling disk.

Figs. 25a,` 25h, and 25o are diagrammatic views illustratingY the relative positions of the stop pin andstart-stop armature under different operating conditions.

Fig. 26 is a perspective view illustrating the shift and carriage-return operating and signaling mechanism.

Referring to ther drawings wherein like reference characters refer to like parts throughout' the several views and more particularly to Fig. 1, the invention is illustrated in the present eX- ample, as applied to a pair of modified Electromatic typewriters A'and B at the sending station A and the receiving station B, respectively, but it is to be expressly understood that any type of standard oiiice typewriter with a modif-led keyboard can be utilized in the novel combination of the present invention and that any number of typewriters can be so interconnected.

Typewriter A comprises an Electromatic typewriter provided with a modified or telegraphic keyboard wherein the typebars are power actuated in a well known manner, upon depression of a chosen character key and wherein a blank key SRKI, controls a send-receive relay (Fig. 4) as will be described in detail later.

Upon depression of any chosen character key, the character is typed on the record sheet 5e at station A and the permutation unit (Fig. 2) is conditioned, as will vbe described later, so that an electrical signal is produced, composed of a predetermined permutation of similar electrical components, which components; by means oi a send-receive distributor assembly, diagrammatically represented in Fig. l, including a novel startstop, single revolution clutch mechanism and send-receive and line relays; are transmitted sequentially over a signal channel represented as a line to the typewriter B at the receive station. It is to be specifically understood that any type of signal channel may be utilized. The respective signal components, when received by the sendreceive distributor assembly at the receive station B, sequentially condition the respective translator magnets (Fig. 11) ci a novel translator mechanism, as will be explained in detail later, whereby the permutation slide bars of the translator are operated to align their respective slots with a certain seeker lever (Fig. '7), in accordance with the particular signal code permutation received. All the seek-er levers are each connected to' a key bar, respectively (Fig. 2), and the key bar at a receive station controlled by the chosen seeker lever corresponds to the character key depressed at the send station.

Alignment of the slots of the siide bars as described above, by the selecting code signal elements of the signal, conditions one selected seel e lever for operation, and upon reception of the seventh or print pulse of the complete signal, the printmagnetPM (Figs. 4 and 1G) is energized to depress the print or drop bar as described in detail later and the selected seeker lever is actuated by its associated spring to operate the corresponding character key at the receive station, so that the same character is typed on the rec-ord sheet D (Fig. 1) at both the send and receive stations. Similarly, any of the letters can be typed and any function 4can be perform-ed, so that any message can be typed at station A and signals set up at station A, which when transmitted to station B, will produce typing of the same message on the machine at that station.

When the operator at station A wishes to send a message to station B, to be simultaneously typed upon both machines, the operator at station A, depresses the blank key SRKI, thereby conditioning the machine at station A for sending, station B being normally in receive condition, all as will be described in detail later. Warning and other signaling means may be provided between stations, in a manner well known in the art but such warning and signaling means do not constitute any part of the present invention.

Referring specifically to Fig. 2, there is illustrated, in skeleton outline only, the mechanism and circuits for the operation of a chosen character key at station A with the consequent mechanical typing of the selected character at station A and the setting up of means for yproducing a signal, representative of the character, whereby such a signal may be transmitted to station B to produce typing of the corresponding character at said station. The operation of the send-conditioned machine to produce a signal for remote operation of a receive-conditioned machine is as follows: Upon depression of a chosen -character key 5l, the key bar 52 is oscillated about its pivot pin 53 against the force of return spring I511 to move an extension arm 55 downwardly. Upon such downward movement, the bifurcated lower end of arm 55 engages a pin 55 on arm 51 integral with the stop lever 58, to thereby rotate stop lever 58 counterclockwise about its pivot I5i). This rotation disengages the channel shaped lug 60 of stop lever 58 from the right hand one of a `pair of detents 6l, on cam E2. An impeller arm 63, in Contact with an impeller lug 64 on cam 62 is constantly urged in a clockwise direction by means of a spring 65 and upon the disengagement of the channel shaped lug 60 of the stop lever from a detent El of the cam, the impeller arm 63, by means of its contact with impeller lug 84, rotates the cam 62, slightly in a clockwise direction, until the cam engages the Vconstantly rotating power roller 6% which is rotated about the stationary shaft @l by means of the typewriter motor (not shown) in a manner well known in the art. The cam 62 by means of its engagement with power rolier 66 is thereupon rotated a full half revolution clockwise, until the other, detent 6l, of the pair of detents on cam 62, engages the channel shaped lug Si! of stop lever 58, in a well known manner. Cam 82 is pivotally mounted by its axis 63 upon an arm 69 of a bell-crank 10 which in turn is mounted for oscillation about a pivot 1I, and upon such rotation of cam 62, its eccentric contour causes a lateral movement of the cam axis 68 to thereby oscillate bell-crank 1U in a counterclockwise direction. Such oscillation causes a downward movement of the arm 69a of bell-crank 18 to thereby lpull down a link 12, to rotate a bellcrank 13 against the force of spring 14 to actuate link to oscillate bell-crank 16 to in turn actuate the type bar 11 to strike one of the type characters 18 against the record 50 (Fig. l), in a manner well known in the art.

Also, upon rotation of cam 62 and consequent lateral movement of the cam axis 68, a roller 19 carried on the lower end of arm 69, is moved laterally to the right, as viewed in Fig. 2. Roller 19 is in engagement with a shoulder 88s on a permutation slider 88 :mounted on suitable slotted guide bars 8| secured to the yframe (not shown) of a typewriter unit. Each slider is provided with spaced studs 82 extending outwardly and alternately from one side and the other of the slider and such studs are carried on both the top and bottom horizontal bars Bilt and 8331), respectively, of the slider member. Rotatably mounted on each of a plurality of code rockshafts 83, and alternately on opposite sides of the sliders, are the diagrammatically represented rockshaft actuating clips 84 which may be of the type as disclosed in the copending application of Harry J. Nichols, Serial No. 353,114 filed August 17, 1940. These clips 84 are removably attached to the rockshafts, as described in said copending application, the relative number and disposition of the clips in the assembly for each slider being dependent upon the particular code value of the character whose key controls the respective slider member. Therefore, upon depression of any chosen character key, the respective code rockshafts 83 to which the clips are attached. will be rotated, as described in said application, and in such a direction that the particular code permutation representing the character, will be set up by the respective permutation switches. It is to be particularly noted, that the universal bail rockshaft 83UB is always actuated -by means of its clip B-fiUB to move one out of a `pair of its controlled switch arms comprising the universal bail switch, momentarily out of engagement, to there- -by produce a spacing condition on the signal channel, this rockshaft .being diagrammatically illustrated as spring biased by means of a coil spring 85 acting through its associated clip SQUB so that the rockshaft and sliderji are returned to their original positions upon completion of the hal-f revolution of cam S2.

Upon the above described lateral movement of the Cam axis, the roller 19 moves slider 88 to the right, as viewed in Fig. 2, against the spring bias eiect of spring 85 acting through clip UB and its cooperating stud, whereby the studs carried by the slider actuate the associated clips and rotate the universal bail rockshaft SUB and such code rockshafts 83, as is required to set up the signal. Such actuation of the clips rotates the associated rockshafts to actuate the diagrammatically represented switch operating elements llUB and B6 to thereby permit the associated spring switch arm 8!UX of the universal bail rockshaft to move out of contact with its associated switch arm SE'UXb and into engagement with switch arm 'iUXa and to force certain of the associated spring switch arms or tongues 81 of the code rockshafts selectively into engagement with the associated switch arms 31a, dependent upon the direction of rotation of the code rockshafts, respectively. It is to be particularly noted, that all code permutation signal settings are differentially produced and only those rockshafts are actuated which require a change from the setting for the previously typed character. If the'same letter is typed twice in succession, the corresponding slider is twice actuated, but only the universal bail rockshait is rotated, the second time, since the remaining rockshafts are retained in their previously set position by the diagrammatically represented associated detent pin 86d, spring pressed, by spring 86s, into engagement with a notch 8611, in the operating element, as described in detail in said copending application. Thus, such permutation switch elements Sia and 87 as are moved into engagement, close a circuit from the positive side of a D. C. source BI, as illustrated diagrammatically in Fig. 2, and the universal bail on the other hand opens the circuit from the positive side of the same source by separation of its pair of contacts 'lUX and SIUXa, in series between the positive side of said source and the distributor assembly. Contacts 8UX and B'IUXb are .simultaneously moved into engagement, to momentarily energize a latching circuit, as described in detail later. Y

The particular permutation of switches closed, will thereby supply positive potential to the sendreceive distributor assembly; including the novel start-stop, single revolution clutch mechanism, send-receive relay and line relay, diagrammatically illustrated in Fig. 2 as the send-receive distributor assembly; which in turn, at the proper time and in proper sequence, will transmit the set-up code permutation of signal components, through the signal channel represented by the line, to the send-receive distributor assembly at the receive station, in a manner to be described in detail later. Upon completion of a full half revolution of the cam 62, the universal bail. rockshaft SSUB is returned to its normal position by spring 85 thereby forcing contacts 'lUX and BTUXb apart and producing closure of contacts B'IUX and lUXa, but the code rockshafts B3 are retained in their actuated positions by the coacting detent pins, until depression of another character key bar. It is seen, therefore, that in a simple and direct manner, a standard oflice typewriter, such as the Electromatic typewriter, modiiied as stated above, can be utilized, to locally type a character and to set up a code signal having a desired permutation of components, characteristic of the selected character, which signal may be transmitted over the signal channel represented by the line, by the novel means now to be described and which may be utilized at a remote typewriter `to type the same character.

The novel communication system comprising the present invention consists of the permuta- Ation means as just briefly described, at each station, for setting up a code signal representative of a character to be remotely typed, a send-receive distributor assembly, comprising in addition to a send-receive relay and a line relay, novel distributor mechanism, and a novel start-stop, single revolution clutch mechanism controlled by the line relay to in turn control the operation of the distributor mechanism at the same station. The code signal set up by the permutation unit, is sequentially transmitted by the sending distributor to maintain synchronism between the distributor mechanisms at the local station and at the remote station and to produce typing of the desired character or performance of the desired function, the remote distributor mechanism controlling novel mechanical translator means, set in accordance with the signal elements received to thereby operate that key bar only, corresponding to the character key depressed at the sending station.

A general description coordinated by reference to the respective figures of the drawings, will first be given, of the essential elements of a complete communication system and then a `detailed description of the sending or transmitting mechanism and circuits and of the receiving mechanism and circuits, including a detailed description of the respective component elements of these mechanisms and circuits will be given, which will be followed by a detailed description of the opertation of the complete system including transmission, reception, break-in, lock-out and other communication functions.

GENERAL DESCRIPTION A plurality of typewriters, such as the machine at station A and the machine at station B (Fig. l) with their respective associated electrical elements, a send-receive distributor assembly including start-stop mechanism and various control elements are interconnected to comprise the novel teleprinting communication system. The system operates on the start-stop, Baudot 5-unit code principle, and by means of associated circuits and mechanisms, two-way transmission of messages over a single channel is provided.

A permutation mechanism, generally as shown described in detail in said copending application, and controlled in the manner as diagrammatically illustrated in Fig. 2, is utilized to produce the start signal by opening the line circuit, to set up a code signal of separate signal components, characteristic of the character represented by a chosen depressed key, and to produce a stop signal. The particular permutation switch elements which are placed in a closed circuit relation by the permutation mechanism close a circuit up to their associated distributor contacts, as illustrated in Figs. 3 and 4, which contacts are sequentially controlled upon rotation of the start-stop clutch, by the transmitting distributor cam, which is driven by the startstop clutch along with the receive cam, the control of said contacts being conventionally illustrated only, in Figs. 3 and 4.

Upon depression of a chosen character key to thereby locally type the character and to simultaneously set up the code signal representative of that character, two of the universal bail contacts are operated to open the line `circuit and thereby release the novel start-stop clutch mechanism of Fig. l'l whereby it is rotated one complete revolution, only, and the selecting code signal permutation, as set up by the permutation unit, is sequentially transmitted to the line by means of the sending distributor unit and the send-receive relay, as diagrammatically illustrated in Figs. 3 and 4l. The line signal elements received at station B, operate a line relay to sequentially control local circuits to the respective contacts of the distributor unit of typewriter B (Fig. l) as this distributor rotates to thereby sequentially and selectively energize the translator magnets (Fig. Il) of the novel translator mechanism of Figs. ll, l2, 13, le and l5, which magnets thereby selectively set the permutation slide bars of the translator so that the one seeker lever, (Fig. 7), and the associated key lever only which corresponds to the chosen character is operated (Fig. 2) upon depression of the print bar at station B (Figs. 2, 8 and lo) to thereby produce remote typing of the chosen character.

Transmitting mechanism The transmitting mechanism comprises the permutation unit of the above mentioned copending application which is controlled by the key bars of the transmitting typewriter, to control circuits leading to contacts controlled by the transmitting cam of the distributor mechanism. The circuits, closed by the transmitting distributor cam, transmit code elements of the signal to a send-receive relay at the send station, which relay controls the transmission of the signal elements through a line relay at the sending station and to a line relay at the receiving. station. The line relay at the sending station, controls the operation of a novel start-stop single revolution clutch mechanism which, in turn, controls the operation of the distributor mechanism. The construction of the permutation unit is as described in detail in said copending application. The construction of the transmitting distributor unit and ranging device of the sendreceive mechanism, the start-stop single revolution clutch mechanism, the shift and carriagereturn mechanisms and the keyboard lock-out or speed lock means, will now be described in detail.

Referring to Fig. 6, the construction and assembly of a novel transmitting or receiving distributor including a novel ranging device are illustrated therein. This distributor is diagrammatically illustrated as separate from the typewriter in Fig. 1, but in actual construction it may be fastened to the back of the typewriter to produce a compact unit.

A transmission cam TC is loosely mounted for rotation about the shaft 88 (Fig. 17) along with a sim'rlar receive cam RC and the other elements as shown in Fig. 17, the receive cam and other elements being omitted in Fig. 6 to clarify the illustration. Transmission cam TC controls a plurality of movable contacts or switch arms of the switches TI, T2, T3, T4 and T5 cooperating with the permutation switches Pl, P2, P3, P4 and P5 (Fig. 3) and each switch including at least av pair of switch arms a and b. The switches T| T6 are in series between the permutation unit switches and the send-receive relay, as diagrammatically illustrated only, in Fig. 3, and thereby control the circuits leading from the respective permutation switches to the line. Cam TC also controls the switch T6 shown as comprising a pair of switches operated simultaneously by means of the web 'I'Ga interconnecting the movable blades a of the two switches.

Referring to Figs. 6 and 6a the horizontal shaft 88 is transversely journaled in ball bearings 89 (only one being shown) forced into suitable recesses 90 bored in the end of a spider 9|, rotatably mounted in the distributor end plate 92 of the distributor mechanism. The shaft 88 is driven by motor means (not shown) to produce rotation of a novel start-stop single revolution clutch mechanism 94 (Fig. 17), as described later, under the control of one of the start-stop magnets SSM or SSMZ diagrammatically illustrated in Figs. 3 and 4.

The send or transmitting cam TC (Figs. 6 and 17) is attached to a spider of the clutch, as described later, for rotation therewith. Upon rotation of the start-stop clutch, the cam TC sequentially closes the a contacts of switches TI to TS, inclusive (Fig. 6), against the cooperating b contact respectively to thereby transmit to the line the elements of a particular code signal, as set by the permutation switches PI to P5, inclusive (Fig. 3), each comprising the pair of contacts 81 and 87a, as described above, and to transmit a stop or marking line signal, as described later. The contacts comprising the switches, each comprises a spring stack-up, as illustrated in Fig. 6, mounted on the spider 9| and distributed about the circumference thereof, whereby, upon rotative adjustment of the spider, as will now be described, the particular timing of the closure of the contacts of the respective switches T| to T6, inclusive, by cam TC, may be adjusted.

The novel ranging device comprises the spider 9| mounted for rotative adjustment about the shaft 88 by means of the spider adjusting plate 98 attached to the spider by screws 98a, and including a slot 98s into which projects the adjustable thumb screw 99 for locking the spider in any desired adjusted position, the relative position being indicated by the index pointer 98p, carried by and movable with the plate 98, and cooperating with the index plate 98h mounted on the distributor end plate. By loosening the thumb screw 99, the spider adjusting plate 98 may be rotatively advanced or retarded, which in turn, advances or retards the time of closure, by cam TC, of the respective switches TI to T6, inclusive, carried by spider 9|. In this manner any shift in phase of the line signal elements may be compensated.

The details of the novel start-stop and single revolution clutch mechanism 94, as shown and described in applicants copending application Serial No. 398,070 led June 14, 1941, are diagrammatically indicated only in Figs. 3 and 4 and are illustrated in Figs. 17 to 23, inclusive. This clutch mechanism comprises generally an overriding roller type clutch in which six small pins or rollers |00 coact with a spider |0| and a pair of driver cups |02 and are engaged by means of a Wedge action to produce a positive drive. After the clutch has been engaged, it continues to rotate, locked in step with the shaft 88 by means of cups |02, until the pawl a, for example, of stop arm 95 engages the stop pin 96. The engagement of the stop pin and pawl arrests the motion of a controller disk 97 to which the pin is attached while the energy of the other parts of the clutch causes the clutch to rotate through a small angle which disengages the rollers |00 and thus releases the clutch.

Referring to Fig. 17, the complete clutch mechanism 94 is illustrated as comprising the pair of driver cups |02 fastened to shaft 88 by means such as set screws |028. Each cup comprises a cylindrical member, bored to ft the shaft 88 and provided with a counterbored portion |02cb turned concentric with shaft 88, the'interior surface of the counterbores constituting the drive surfaces of the clutch. Located between the pair of driver cups is the spider |0| (Fig. 18) mounted on and in loose contacts with the shaft 88 and extending at its ends into the interior of the counterbored portions of the cups. The rollers |09 are mounted in axially extending slots or grooves |8|s (Fig. 18) formed in the outer periphery of the spider and the ends of the rollers are so positioned as to contact the interior surfaces of the respective counterbores |020?) of the respective cups when the clutch is engaged. As is seen in Figs. 18 and 19, the slots lllls are formed eccentrically with respect to the shaft 88 so that motion of the rollers |60 along the bottom of the slots or grooves, moves the rollers further from the center line of the shaft or closer thereto in accordance with the direction of motion, so that the rollers are either thereby engaged or disengaged from the driver cups |62. The driving rollers |00 are jointly controlled by an in` `-teriorly toothed controller disk or ringlll (Fig. which ring is rotatably mounted in a radially era-ting camA IEM.

I engaged position.

spider.

extending groove Itlg (Fig. 18) formed-in the spider lill Aand is provided with a` torquey spring |83 (Fig. 23) having one endfinserted into lan 1. axially extending opening-91a. inthe controller in turn is urged into engagementwith the rollers f by a cup-shapedspringwasher It bearing on the bottom of the counterbores Icb of the cups 152, respectively, 'so that a force is always exerted upon the A'rollers-by the rotation of the drivercups to" aid in'positioningthe pins in the lBy adjustment or" the position of the cups Ion the shaftV 88," the frictional force -on the spider maybevaried. -A notch-or axially-'extending slot-t61- (Figs. 6 aridlS) is formed inthe outer-edge of one ofYV the radially extending members Ilr of the spider-andfa driving-key I8l(Figs. 6 and 2.4) fastens the transmitting cam -'-TC, latch Contact operating cam Il,(Fig. 17), circuit breaker cam Iiland 'receivecam VRC to the spider IBI for rotation therewith upon release of the controller ring'gl and engagement of theclutch.

As illustrated in Figs. 20 and 2l, the controller ring is provided Awith lastop pin cooperating `with the pawls-'Sia and-S51) on the arm 95 (Fig.

V) controlled by the armature SSMA of the start-stop magnet SSM. Engagement of the pin Qt with either the pawl 95a or-Sb, Aholds the controller ring 9?- inl position, against the force vof the torque exerting spring I t3, so that the rollers v Iii@- are'held,out of the interlocking engagement,

Ybetween the rollers, the driver cups Yand vthe 'This condition is-illustrated-in Figs. 19 and I"20, Y the stop arm- 95 being schematically illustrated as-engaging the stop pin''. The teeth gli (FigLZO) ofthe` controller ring 91 held the rollers It@ in the position as show-n in- Fig; i9, so that the rollersare located in t-he deepest part of `the slotsV llsfof the-spiderand the-rollersfare therefore out of engagement with the peripheries of counterbores H9202), respectively. Upon-release ofl the stop pin 195, as illustrated diagram- -rnatically in Fig. 2l, the controller ring 91 -is rotated byspring-Iii. Simultaneously, the-friction due to washer- IE5 (Fig-17) land cupshaped spring washer Ii tends to rotatev the spider lill in the direction of rotation of the clutch.

In order to obtain positive and rapid engagement of the drivingpins, by the ring orcontroller disk'ifto lock the drivingcups tothe spider, the` controller ring not only must be-accelerated bythe accelerating spring ID3, -as'just described, but the spider mustbe held stationary in the meantime. As is seen in Fig. 24, the hub Iiia of cam H34 is provided-with a -Vnotch I Ib Vinto-which projects the V-shaped end I ma ofthe detent lever'lli. Since the spider lill is connectedV to cam IM by key Hi8 (Figf24) the-lever IH) holds the spider stationary when the clutch is disengaged. Therefore, although the friction of members H35 and It tend to rotate the-spider, as above stated, the detent lever holds the spider against such immediate rotation. The springl ISS, therefore. snaps the ring S7 into rotationand the ringV or controller disk teeth 'it quickly-assume 'thepositionj as shown in Fig-'22, to thereby-move the" pins i60 in-to the-shallow'parts of the groove I-Is-'so that the rollers engage the-surfaces of the -counterbores `i-Zcbv formed linY the cups vIEI2 varid the clutch isfrotated. Upon the engagement of pinf at the end-of a revolution of the ciutch,

'the ring'tl'lI is-arrestedY and the momentum Voithe other parts of the clutch rotates the spider until lever-II engages the notch Hilo-so that the spider assumes the position -of Fig.v 19, the rotation of cam IM, with respect to` rings?, before itis stopped by lever i It, thereby p1acing-a stress `on spring IGS, to condition the same Vfor the next cycle of operation.

The complete operation `of the novel start-stop single'revolution clutch *mechanism of Figs. 17

to-23,inclusive, is as follows: litespondingto a Vspacing line condition, the'start-sto-p magnet 'of rotation of the pini and pawli is moved into the-'path ot rotation of this pin thereby stopping the clutch in the preliminary stop position uponthe engagementof pin 1% and pawl This is the position'oi the clutch when the system is deenergized and is not in use.

Uponfdepression'of the send-receive key SRK! (Figjfi) at the transmitting station A, for example, the line is-energized, thereby-energizing start-stop magnet SSMI at this'station, as Ywillbe explained in detail later. The armatureSSMA VofSSMi isthereby attracted as diagrammatically shown in Fig. 4, so that armis rotated Lounterclockwise against the force of spring's to the position, ass-hown in Fig- 25h, and the pawlb is rotatedinto "position to intercept the 'stop pinl' so that the clutch is yarrested in the `normal stop position (Fig. 4).

lNow, upon transmission of the normal start or spacing line condition, magnet SSMI is deener- `gized'and the arm 95V is `rotated counterclockwise Vto the position,as shown in Fig. 25C. As is clearly illustrated inthe diagrammatic illustration of -Fig.-25c,this release will permit the pin to `clear both of the pawls 95a and 95h and such release of pin 96 permits ringS'I under control of spring H33, as described-above, to move the rollers -into engagement with the cups to rotate clutch Ynorrnal operation because a stop or marking line condition is transmitted-as they last signal, component of `a complete signal which stop signal 'energizes magnet SSM! to attract armature SSMA to rotate arm S5 to the position,as shown Iin Fig.25,land-diagrammatically illustrated only, 'in Fig.- 4. Such engagement of pin'tlstops the clutch and resets springV H33, as described above.

Rotation of the start-stop clutch produces rotation ofthe cam 'TC (Figsd3, 4, 6.and" 17), cam I (Figs. 4 and`17), caml) (Figs. 4.and 17) and cam RC (Figs. 3,4 andY 17) Yand rotation of the cam TC (Figs. 3, 4, 6 and 17) for example, sequentially operates the transmitting switches TI-T6, inclusive.' as previously explained. yUpon receipt of the stop signal near the end of one cycle of operation,I thestart-stop magnet is energized .to stop the clutchin the normal stop. position, as previously described, thereby limiting the start-stop clutch mechanism 94 to a single revolution only.

Mechanism for locally producing shift or carriage-return and simultaneously p-roducing a letters or gures shift signal or a carriage-return signal for remote control of these functions, will now be described. Referring to Fig. 26, a standard power cam III for locally producing letters or figures shift, which shift cam is, as is well known, normally operative upon the downward stroke and also operative on the upward stroke, is operatively connected for control thereby in the well known manner, to an extension H2a of an auxiliary key lever H2, in this instance, instead of being operatively connected to the standard figs key lever 52F. Key levers H2 and 52F are mounted for rotation about the cylindrical rod element H3, in a manner well known in the art, the key lever SBF by means of its extension 55 controlling a single half revolution cam 62, as in Fig. 2.

The figs key lever 52F is remotely controlled, as diagrammatically illustrated in Fig. 2, upon reception of a signal, by a seeker lever SL, and its connecting pin SLP extending into a key bar slot 55S. The power shift cam, when operated by remote control or when manually operated through the digital operation of the rigs key 5IF controls, in a normal manner, the shifting of t the typewriter basket locally, to figs case, by operation of key lever H2 and consequent downward stroke of extension H2a, while upon the upward stroke of lever H2 produced, by means of interconnecting mechanism as will be presently described, by depression of the letters key SIL, the basket is locallyshifted to the letters case. The letters key lever 52L may be remotely controlled by means of a seeker lever, in the same manner as the remote control of lever 52F, or it may be digitally operated. The letters key lever 52L, by means of its extension 55, controls a standard, single half revolution power cam 62 having a slider actuating roller I9 mounted on an extension of the support arm thereof, as in Fig. 2. g

A rocker lever H4 is pivotally mounted on the frame H5 by means of a pivot screw H6. An inverted L-shaped lug ||`I integral with the left end of the lever H4 engages in an opening HZb formed in the auxiliary key lever I2. key lever 52F, in its unoperated position, abuts the top of the rocker lever I I4, and upon depression, of the key SIF, will rotate the rocker lever counterclockwise. Likewise, the letters key lever 5.2L in its unoperated position, abuts the top of the rocker lever and upon depression of this key lever it produces clockwise rotation of the rocker lever. A spring arm H8, attached to the frame H5, is provided with a circular, protruding element H9 which engages in either an upper indentation |20 or a lower indentation |2| formed in the right hand end of the rocker lever I I4. When the rocker lever is rotated clockwise upon depression of the letters key 5IL, the protruding element I I9 engages the top indentation |20 of lever H4, as shown in Fig. 26, to thereby hold the rocker lever in the extreme clockwise position. Likewise, when the lever H4 is rotated counterclockwise by depression of the figs key 5|F, the element I I9 engages the lower indentation |2| to hold the lever H4 in its eX- treme counterclockwise position.

The operation is as follows: The figs key 5|F is first depressed and allowed to return to its normal position. Depression of the rigs key The figs not only releases its associated cam 62, in the well known manner, to permit roller I9 to operate the associated slider, as in Fig. 2, to set up the permutation code signal characteristic of iigs shift but also rotates the rocking lever H4 counterclockwise, and this lever is held in the eXtreme counterclockwise position by means of spring arm H8, element H9 and indentation |2I. Counterclockwise rotation of the rocker lever depresses the key lever H2 by means of the in- Verted L-shaped lug II'I integral with the lever H4. Upon depression of lever H2, this lever remains down, releasing cam I I I for a half revolution only, whereby the type basket is locally shifted to the rigs case and will remain in that condition until the letters key is depressed.

Upon depression and release of the letters key 5 IL, on the other hand, not only is its associated cam S2 released to rotate a half revolution, so that its roller I9 will operate its associated slider, in a manner now well understood, to set up the permutation code signal representative of letters shift, but also the rocker lever H4 is, this time, rotated clockwise to thereby raise lever H2 to release cam III for another half revolution whereby the type basket is locally shifted to letters case.

Successive depressions of the figs key or of the letters key will permit repeat signals to be transmitted to the line but will not at all affect the rocker lever H4, so that the typewriter` basket will locally remain in either iigs case or letters case, depending upon whether the figs key or letters key is being successively depressed.

There is also disclosed in Fig. 26, a novel carriage-return signaling and operating arrangement. It is to be noted, at this point, that in the standard Electromatic typewriter, the carriagereturn power cam is of the single lobe type, in contrast to the ordinary double lobe type, such as is illustrated in Fig. 2. Upon actuation of the carriage-return key, the single lobe cam is locked in operative position until the typewriter carriage completely returns to the left hand margin. Due to the variable operating time of the carriage-return cam, means must be provided to produce a signal, corresponding to carriage-return, which will occupy the same time interval as all other signals.

Referring to Fig. 26, a carriage-return lever 52CR is mounted for rotation about the rod H3 as a pivot, in the well known manner. An auxiliary lever |22 is likewise mounted for rotation about rod I I3. A generally U-shaped connecting link |23 is pivotally mounted in a bracket |24 fastened to a part of the frame, by any well known means. One end of the link |23 engages in an opening formed in the key lever 52CR while the opposite end of the link |23 engages in an opening formed in the lever |22. The carriagereturn lever 52CR, controls the usual single lobe cam (not shown) producing carriagereturn locally. The lever |22, controls an ordinary twolobe power cam (not shown) in the same manner generally, as lever 52L, for example.

The operation is as follows: upon depression of the carriage-return key 5CR, a single lobe power cam is released and the carriage at the local machine is returned to its left hand margin.

Simultaneously, upon depression of the key 5|CR, the lever 52CR is depressed and the link |23 operated thereby depresses lever |22 thereby releasing the ordinary two-lobe power cam such as 62, associated therewith, to set up the carriage-return signal permutation so that con- `se'quently the machine at the remote station is controlled by the received signal to operate the carriage-return lever atsaid remote station and thereby produce a return of the carriage at the remote station, to its left hand margin. YEy utilizing the combination of lever 52GB and lever |22 with the respective cams, as controlled by these levers, the function ofYcarriage-return is produced locally, in the usual' manner, and a carriage-return signal, of equal duration to all other character or function representing signals, is transmitted to a remote station.

The details of the keyboard lock-out or speed lock mechanism which comprise a partof the novel break-in means is disclosed in Fig. 5. This keyboard lock-out is of the type as disclosed in the copending application of Henry L. Tholstrup, Serial No. 298,005, iiled October 5, `1939,vnow Patent 2,255,030 granted September 2, `1941.

Referring to Fig.5, `the lock-out means are seen as comprisin'I a comb 'IE5 oi `thetypewriter 'provided with a locloout mechanism comprising a plurality of rollers |26, mounted in a roller guide I2?, these rollers being of such diameter and so spaced that only one key llever or the lock-outvlever only, can be depressed at any onetime, A lock-out lever |28, similar to the ordinary key lever of a typewriter, is mounted, by means of rod H3, for oscillation in a vertical plane about said rod 'as a pivot. A spring |23, attached by a hook i3@ to the lever E28 at one end 'thereof and fastenedto the frame ofthe typewriter by means such as I3! at the-other end thereof, biases the lever against the top of a guide slot I3! in the comb |25.

A coil spring |32 having one end -lt thereof threaded through an opening in lever |28, is connected at its other end to a lug |'35integral with the top of plunger l 38 comprising the armature of a lock-out or l-atch magnet LM (see also Fig. 4) mounted in the U-shaped base i3?. The energization of latch magnet -LM is controlled by the novel break-in system which will be described in detail later.

The operation of the lock-out is as follows: Upon energization of the magnet Ll/L'the plunger or armature |35 is drawn downwardly, as Viewed in Fig. 5, applying a force to the coil spring |32 whereby the lock-out lever is oscillated, about the rod H3 as a pivot, against the force of bias spring 129 and thereupon lever |28 is pulled downwardly to the bottom of the guide slot |3| and between'a pair of the `rollers |26 whereby the spacing'between the rollers is so decreased, that no key lever of the typewriter can now enter therebetween until lever |28 is retracted by the spring |29 upon deenergization of magnet LM. The utilization of the flock-out means in combination with a novel break-in system, will be described in detail later.

Receiving mechanism The receiving mechanisms and related circuits are illustrated diagrammatically only, in Figs. 3 and 4, and it is tobe particularly noted that such circuits and such mechanisms are provided at both the sending and receiving machines. It is also to be particularly noted, as described above, that elements of the transmitting mechanism and of the receiving mechanism at any one station are both mounted upon a single shaft 38 for operation bythe same clutch Sli, as illustrated diagrammatically in Figs. `3 and 4. 'The receiving mechanism comprises a receive cam RC .similar in construction to the transmission cam TC (Fig. 6) and mounted on the same shaft 38 as the transmitting cam, as diagrammatically illustrated in Figs. 3 and 4. This receiving cam controls a plurality of switches'Ri, R5, R4, R5 and R5, each including. at least a pair of switch elements a and b, and similar to the transmission switches yTl to T, inclusive, as illustrated in Fig. 6. As is seen from Figs. 3 and 4, the contacts comprising the individual switches Ri to R5, inclusive, are series with a power source; through the contacts of the send-receive relay, the permutation slide bar magnets M to M5, inclusive, and the armature of line relay LRE, for example, and printing magnet PM; and switch is similarly in series with the start-stop magnet solenoid SSM; whereby the switches Ri to R5, sequentially and selectively control the current through the permutation slide bar magnets and switch Rij controls the energization of SSMZ in accordance with the characteristic of the received code signal permutation elements, respectively. Since the receive cam RC is controlled by the same clutch S4 as the transmitting cam TC, the two cams at any one machine are rotated in unison. Means are provided, as described in detail later, for rendering the receive cam and its associated switches at the sending station, ineffective during transmission, while the receive cam, at the receiving station, is released for'rotation in step with the transmitter cam at the sending station, all as described later.

Referring to Figs. '7 to 16, inclusive, the construction, arrangement and manner of operation ofthe signal storage mechanism, including an overlap arrangement, will `now be described in detail. rThis signal storage mechanism is of the mechanical storage type,'as shown and described in applicants ccpending application Serial No. 398,068, led June 14, `1941, wherein the translator or permutation slide bars are selectively positioned, in accordance with the character of the respective signal elements comprising a received line code signal permutation, to align a certain series of notches in the respective bars, so that one seeker lever only, will be operated, to thereby operate its associated key lever upon operation of the drop or print bar, when the latter is actuated in response to a timed local impulse from print segment PS 'of the receive distributor. The translator is mounted in the typewriter directly beneath the key levers and above the permutation unit.

Referring to Figs. 11, 12 and 13, the translator unit is shown as comprising a plurality of ve permutation slide bars |38, separated by elongated rollers |38 (Figs. 12 and 13) mounted in openings it@ in the respective slide bars. The bars are slidably mounted on cross members Ml. A pair of brackets I d2, attached to cross membrs Uli by screws |43, serve to securely fasten the translator unit in place beneath the key levers. Support members |44 and I i5 maintain the bars in proper alignment andprevent lateral separation of the bars. The permutation slide bars are provided with notches arranged in accordance with the Baudot code, so that, upon relative longitudinal arrangement of the bars, selectively in accordance with the elements of a received code signal permutation, only one series of slots will be aligned for 'any one signal permutation received. A stop member `|46 fastened vby screws |41 to one ofthe cross members I 4| cooperates with an extension |38a on each permutation bar to limit the longitudinal movement of the bar, when it is released by the permutation bar magnet corresponding thereto. A coil spring |48, is provided for each slide bar, having a hook |48a at one end attached to the corresponding bar by insertion into an opening |381) in the bar and the opposite end is maintained in position by a pin |49 passing through an eye |482), the pin abutting an angle member |50 attached to one of the cross members |4| by screws |5| (Fig. 11). The permutation slide bars are positioned in their extreme left hand position, by means of the restore magnet RM (Fig. 15) controlling its armature RMA carrying the restore arm |52 extending into each of the notches |38c formed in the permutation slide bars. Upon energization of the restore magnet, as will be described in detail later, its armature is attracted and the restore arm |52 engaging a side of a notch |380, moves the slide bars against the force of their bias springs |43, to the left, to their eXtreme left hand position, as illustrated in Fig. 11. A series of permutation slide bar magnets MI to M5, inclusive, one for each slide bar respectively, is provided and their armatures provided with latches maintain the slide bars in the extreme left hand position, as described presently, when the magnets are deenergized, and upon energization of the magnets by received signal elements they selectively release the slide bars from said position, in accordance with the particular code signal permutation received. Each of the translator magnets, such as M4 of Fig. 11, for example, is mounted on a frame |53 attached to the front plate |54 by means of screws |55, which plate in turn is attached to the cross members |4| by screws |56. Each magnet is provided with an armature |51, mounted for oscillation about a pair of pivot points |53 carried by frame |53. Armature |51 is provided with a latch member |51| (Figs. 12 and 14) at one end and is urged to the position as illustrated in Fig. 11 against a stop (not shown) by means of a spring bias member |59 whose biasing force is adjusted by means of an adjustable screw |68. When the restore magnet RM has been energized to restore the slide bars |38to their extreme left hand position, as illustrated in Figs. 11 and 12, the latches when magnets M! to M5 are deenergized, abut a shoulder |38d, on each slide bar |38, to hold the bar in position against the force of its related spring |48. Upon selective energization of any of the permutation slide bar magnets, in accordance with the respective received code permutation elements, the energized magnet, such as M4, for example. attracts its armature |51 to thereby disengage the latch |51| from the shoulder |38d (Fig, 12) whereupon the spring |48 pulls the slide bar to the right, to the position as illustrated in Figs. 14 and l5. The particular permutation of slide bars, so released, determines the particular array of notches which is aligned, which in turn determines the particular seeker lever, that can enter the aligned notches, which seeker lever upon operation of the print bar, depress its connected key lever to operate the same. as illustrated diagrammatically in Fig. 2.

As illustrated in Fig. 16, certain of the permutation slide bar magnets, such as MI and M2, for example, may be provided with novel means whereby the slide bar magnet is maintained energized long enough for the restore magnet to 0perate fully, which latter operation may not occur until the first and second selecting code signal elements of the next succeeding character signal have been transmitted over the line and received at the receive station, whereby the full signal transmitting capacity of the system may be utilized.

As is seen in Fig. 16, a permutation slide bar magnet such as MI or M2, for example, comprises a core |6I upon which is wound a low resistance coil |62 of comparatively few turns concentrated at the armature end of the core. In series with coil |62 is a high resistance winding |53 of several thousand turns occupying the heel end of the core and shunted by a storing condenser |64. When the local pulse, corresponding to a received code signal permutation element, is applied to the winding of the corresponding magnet, a rush of current flows through the low resistance winding |62 into the storing condenser |64, which, because of its large capacity, offers comparatively little impedance to such rush of current and hence the current magnetizes the core |62 at the armature end to attract the armature |51 so that the latch |51| assumes the position as illustrated in Fig. 14. The electrical energy thus stored in condenser |54, combined with that stored in the coil, maintains the core energized after decay of the local pulse, to thereby hold the armature in the position shown in Fig. 14, for a time interval determined by the electrical constants of the condenser and coil. The armatures |51 of magnets MI and M2, are thus maintained in the position as illustrated in Fig. 14, until the restore magnet RM has operated its restore arm |52 (Fig. 15) to restore all of the permutation slide bars to the position as illustrated in Figs. 11 and 12, and alsountil the restore magnet RM has been deenergized, so that the slide bars |38, corresponding to magnets MI and M2, respectively, are released and moved to the right by their springs |48, so that the respective shoulders |38d are in the position as illustrated in Fig. 15, whereupon the magnets MI and M2 may release their armatures and latches |51I, without interfering with the setting of the permutation bars in accordance with the first two selecting components of a succeeding received code signal permutation.

Referring to Figs. 8 and 9, there is diagrammatically illustrated therein, a drop or printing bar |65 and its associated operating mechanism. Print or drop bar |65 is supported for movement in a plane parallel to the plane of the permutation slide bars. Novel means are provided for producing movement of the drop bar in response to an element of the code signal permutation received. Referring to Fig. 11, the print bar |65 is supported between tabs |65a and the support members |45, respectively. Piston members |65` (Fig. 9a) mounted for movement vertically in the cross bars |4| (Fig. 8) are provided with rounded ends |660, fitted into corresponding sockets in the print bar. A pair of toggle links |61 are connected to the piston members, respectively, at the lower split end thereof, by means such as a pin |68, and a pair of double toggle links |59, each pair held together by a screw |69a passing through a spacer |6917, are connected at one end to the lower end of link |61, bv a combined pin and pivot element |6111 (Fig. 9b) and are pivotally mounted at the other end by means of a screw |18 passing through a spacer |1| (Fig. 9) and connected to the bracket |12 which, in turn, is fastened to a cross bar |4| by screws |13. A tie rod |14 is threadedly con- 

